Bone cleaning assembly

ABSTRACT

A cleaning module for cleaning bone stock used in surgical procedures. The cleaning module includes a shell. The shell defines a void space to receive the bone stock. A cutter is rotating mounted in the void space. A shaving tube, also able to rotate, is coaxially disposed about the cutter. The cutter and shaving tube have complementary edges. A drive assembly rotates the cutter and shaving tube at different speeds, at different times or in different directions relative to the cutter. As a result of the rotation of the cutter and shaving tube soft tissue adhering to the bone stock is cut away from the bone stock by the relative rotating of the cutting edges of the cutter and shaving tube.

RELATIONSHIP TO EARLIER FILED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/627,488 filed 20 Jun. 2017. U.S. patent application Ser. No.15/627,488 is a divisional of U.S. patent application Ser. No.14/311,674 filed 23 Jun. 2014 now U.S. Pat. No. 9,687,361. U.S. patentapplication Ser. No. 14/311,674 is a continuation of PCT Pat. App. No.PCT/US2012/072160 filed 28 Dec. 2012. PCT App. No. PCT/US2012/072160 isa non-provisional application that claims priority from U.S. Prov. Pat.App. No. 61/581,310 filed 29 Dec. 2011. The contents of theabove-identified applications from which this application claimspriority are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to an assembly able to clean bone stock for usein surgical procedures.

BACKGROUND OF THE INVENTION

In certain surgical procedures chip-sized bone is used as filleradjacent intact bone. For example, in a spinal fusion procedure, it isknown to place a compound formed out of milled bone chips aroundimplanted rods. The rods hold adjacent vertebrae in alignment. Thiscompound serves as a lattice upon which tissues forming the vertebraegrow so as to form a foundation of bone around the rods. This foundationdistributes the load imposed on the rods. Bone chips can also be placedin the intervertebral disc space or into a cage positioned in theintervertebral disc space.

Bone chips are also used as filler and/or growth formation lattice inorthopedic surgical procedures and maxillofacial procedures. Bone chipsare used as a filler and/or growth formation lattice in these proceduresbecause the proteins from which the bone is formed serve as make-upmaterial from which the blast cells of the adjacent living bone cellsform new bone.

The ideal source of bone stock for bone chips is the patient into whomthe bone chips are to be packed. This is because the patient's own boneis less likely than donor bone to be rejected by the patient's immunesystem. Accordingly, in a procedure in which bone chips are required,bone stock is often harvested from one of the patient's bones that canafford to lose a small section of bone, typically between 0.25 and 3cubic centimeters. Bone that is removed from the patient for transplantinto another part of the patient is referred to as autograft bone.

Converting autograft bone stock into bone chips can generally beconsidered a two part process. In the first part of the process, theharvested bone is cleaned to remove the ligaments and other soft tissuethat is not suitable for forming bone chips. The cleaned bone is thenmilled into bone chips. The Applicant's Assignee's U.S. PatentApplication Pub. No. US 2009/0118735 A1 and PCT Pub. No. WO 2009/061728A1, BONE MILL INCLUDING A BASE AND A MILL HEAD SEPARATE FROM THE BASE,THE MILL HEAD INCLUDING A REMOVABLE CATCH TRAY, the contents of whichare hereby incorporated by reference, discloses an electrically operatedbone mill capable of converting bone stock into bone chips.

In a typical bone cleaning process, prior to milling the bone, surgicalpersonnel manually clean the bone. Presently, surgical personnel performthis manual process using curettes and/or rongeurs. It may take 15minutes or more for surgical personnel to perform this task.

Moreover, to perform the cleaning process, the surgical personnel mayneed to firmly grasp the bone. Exerting such force on the bone may causetearing of the gloves worn by the surgical personnel. Furthermore, thesharp cutting tools being used by the surgical personnel could cut ortear through the gloves. Such cutting or tearing through the glovescould result in the possibility that skin of the surgical personnel maycome into direct contact with the bone. This contact can result incontamination of the bone.

Therefore, there is a need in the art for assemblies that remove softtissue from bone while reducing the need for manual grasping andcleaning of the bone.

SUMMARY OF THE INVENTION

This invention provides an assembly for cleaning bone stock. Theassembly comprises a shell defining a void space for receiving the bonestock to be cleaned. A cutter is disposed in the void space so that,when actuated, the cutter cleans the bone stock by removing soft tissuefrom the bone stock. A guide moves between a disengaged position and anengaged position. The guide is configured to, when out of the disengagedposition, move bone stock received in the void space toward the cutter.

This invention also provides another assembly for cleaning bone stock.This assembly includes a shell defining a void space for receiving thebone stock to be cleaned. A cutter is disposed in the void space sothat, when actuated, the cutter cleans the bone stock by removing softtissue from the bone stock. A shaving tube is coaxially disposed aboutthe cutter and is supported by the shell. The cutter and the shavingtube are configured to rotate at different speeds or directions relativeto one another.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Advantages of the invention will be readily appreciated as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswherein:

FIG. 1 is an elevational view of a system for cleaning bone stockincluding a base unit, a cleaning module, a drive module, and a console;

FIG. 2 is a perspective view of the base unit of FIG. 1;

FIG. 3 is a perspective view of the cleaning module and drive module;

FIG. 4 is an exploded perspective view of the cleaning module;

FIG. 5 is an exploded perspective view of the drive module;

FIG. 6 is a cross-sectional view of the cleaning module and drivemodule;

FIG. 7 is a perspective view of the cleaning module with a cap and lidremoved;

FIGS. 8 and 9 are top perspective views of a cutter, guide, shavingtube, and tumble plate;

FIG. 10 is a top view of the cutter, guide, shaving tube, and tumbleplate illustrating different positions;

FIG. 11 is a close-up of FIG. 10 illustrating interaction between thecutter, shaving tube, and guide with a horizontal cross-section takenthrough the cutter and shaving tube;

FIG. 11A is a close-up of FIG. 10 illustrating interaction between thecutter, shaving tube, bone stock, and guide with a horizontalcross-section taken through the cutter and shaving tube;

FIG. 12 is a top perspective view of the guide;

FIG. 13 is a bottom perspective view of the guide;

FIG. 14 is a top perspective view of the cutter;

FIG. 15 is an elevational view of the cutter;

FIG. 16 is a close-up of a flute and cutting edge of the cutter of FIGS.14 and 15 viewed from below the cutter;

FIGS. 14A-16A are views similar to the views of FIGS. 14-16 of analternative cutter;

FIGS. 14B-16B are views similar to the views of FIGS. 14-16 of a secondalternative cutter;

FIG. 17 is a top perspective view of the shaving tube;

FIG. 18 is a bottom perspective view of the shaving tube;

FIG. 19 is a perspective view of the tumble plate with integrated gear;

FIG. 20 is a top view of the tumble plate;

FIG. 21 is an exploded perspective view of the cleaning module and drivemodule showing their alignment for connection;

FIG. 22 is an exploded perspective view of the cleaning module and drivemodule without their shells;

FIG. 23A is a partial perspective view showing a lower portion of a hubof the guide and a cam follower;

FIGS. 23B-23E are schematic illustrations of movement of the camfollower and corresponding movement of the guide with FIG. 23B showingthe guide in an extreme clockwise position, FIG. 23C showing the guidemomentarily in the extreme clockwise position, FIG. 23D showing theguide in the extreme counterclockwise position, and FIG. 23E showing theguide in an engaged position with bone stock trapped between the guideand cutter;

FIG. 23F is a cross-sectional view taken through the hub of guide andthe cam follower;

FIG. 24 is a top view of a cam gear;

FIG. 25 is a bottom perspective view of the cam gear showing an indexerpin that cooperates with the indexing gear;

FIG. 26 is a top view of the indexing gear illustrating operation of theindexer pin sliding in an indexing groove in the indexing gear;

FIG. 27 is a bottom perspective view of a cam follower;

FIG. 28 is a top perspective view of the cam follower;

FIG. 29 is an elevational view of an alternative system for cleaningbone stock;

FIG. 30 is a perspective view of an alternative cleaning module;

FIG. 31 is an exploded perspective view of the alternative cleaningmodule;

FIG. 32 is a cross-sectional view of the alternative cleaning module;

FIG. 33 is a cross-sectional top view of an arm and a containment ringof the alternative cleaning module;

FIG. 34 is an upper cross-sectional perspective view of the arm and thecontainment ring of the alternative cleaning module;

FIG. 35 is an enlarged, fragmentary view of FIG. 34 illustratingengagement of the arm and a shaving tube of the alternative cleaningmodule;

FIG. 36 is a partial cross-sectional view of the alternative cleaningmodule;

FIG. 37 is a perspective view of an arm of the alternative cleaningmodule;

FIG. 38 is a top view of the arm of the alternative cleaning module;

FIG. 39 is a bottom view of the arm of the alternative cleaning module;

FIG. 40 is a perspective view of a containment ring of the alternativecleaning module;

FIG. 41 is a top view of the containment ring of the alternativecleaning module;

FIG. 42 is a perspective view of a cutter of the alternative cleaningmodule;

FIG. 43 is a side view of the cutter of the alternative cleaning module;

FIG. 44 is an end view of the cutter of the alternative cleaning module;

FIG. 45 is a perspective view of a shaving tube of the alternativecleaning module;

FIG. 46 is a side view of the shaving tube of the alternative cleaningmodule;

FIG. 47 is a cross-sectional view of the shaving tube taken generallyalong line 47-47 in FIG. 46;

FIG. 48 is a top view of a pair of debris catches of the alternativecleaning module;

FIG. 49 is a perspective view of one of the debris catches of FIG. 48;and

FIG. 50 is a side view of the debris catches of FIG. 48 mated together.

DETAILED DESCRIPTION I. Assembly

Referring to the Figures, a bone cleaning system for cleaning bone stockis generally shown at 40 in FIG. 1.

System 40 includes a base unit 42. Internal to the base unit 42 is adrive motor 44. A drive module 45 is configured to be removablyattachable to the base unit 42 for coupling to the motor 44. A cleaningmodule 46, for cleaning bone stock, is removably attachable to the drivemodule 45. In the embodiment shown, the base unit 42 and drive module 45are reusable, while the cleaning module 46 is disposable for discardingafter the bone stock is cleaned.

The cleaning module 46 includes at least one cutter 48 for cutting softtissue from bone stock (see FIGS. 4 and 7). Cleaning module 46 isconfigured so that, when attached to the drive module 45 positioned onbase unit 42, cutter 48 is operatively connected to the motor 44 thoughthe drive module 45 so as to be actuated by the motor 44.

Harvested bone stock is placed in the cleaning module 46. The motor 44is actuated so as to result in an actuation of the cutter 48. The actionof the cutter 48 cuts the soft tissue and other debris from the bonestock while leaving a progenitor layer around the bone in place.

A control console 50 supplies electrical energization signals to themotor 44 to actuate the motor 44. Cable 52 is connected between the baseunit 42 and console 50. Cable 52 contains the conductors (notillustrated) over which the energization signals are supplied from theconsole 50 to the motor 44.

The base unit 42 includes a circular foot 54. A leg 56 extends upwardlyfrom foot 54. Leg 56 is tubular in shape and has a circular crosssection. A pedestal 58 is disposed on top of the leg 56. The pedestal 58tapers radially outwardly from the leg 56.

Referring to FIG. 2, pedestal 58 has a generally circular top surface60. The pedestal is further formed to have a lip 62 that extendsupwardly and extends about the perimeter of the top surface 60. Topsurface 60 and the radially inner surface of lip 62 define asubstantially cylindrical mounting space 64 within pedestal 58. Mountingspace 64 is open at the top of the pedestal 58. The outer circumferenceof lip 62, which is the outer circumference of the pedestal 58, issmaller than a circumference of the foot 54. The outer circumference oflip 62 is larger than that of leg 56. Pedestal 58 is further formed soas to have an opening 66 in the center of top surface 60.

Notch 68 extends radially inwardly from the outer circumference ofpedestal 58. Notch 68 thus forms a break in lip 62. In the illustratedversion of the invention notch 68 extends radially inwardly to centeropening 66. The pedestal 58 further includes a number ofcircumferentially and equiangularly spaced apart teeth 70 (only twoteeth shown in FIG. 2). Each tooth 70 extends upwardly from the pedestaltop surface 60 adjacent lip 62.

Two retention arms 72 are pivotally mounted to the pedestal 58.Retention arms 72 are diametrically opposed and mounted to the pedestal58 in cutouts formed in the lip 62 (cutouts not separately numbered).

Each retention arm 72 has a finger 74 that, when the arm 72 is at rest,extends over a portion of the perimeter of pedestal top surface 60. Whenthe retention arms 72 are so positioned, the arms 72 are in the “locked”state.

Each retention arm 72 has a lever 76 located below the pedestal 58. Bymoving lever 76 radially inwardly, towards the underside of the pedestal58, the associated retention arm 72 is pivoted relative to the pedestal58 so as to move the corresponding finger 74 away from its position overthe pedestal top surface 60 and out of its locked state. When theretention arms 72 are so positioned, the arms 72 are in the “released”state.

A biasing device such as a spring (not illustrated) is disposed betweenan inner surface of the pedestal 58 and each arm 72. The spring biasesits respective retention arm 72 towards its locked state. Each retentionarm 72 may be biased into its locked state by a dedicated spring.Alternatively, both retention arms 72 may be biased into their lockedstates by a common, shared spring.

Motor 44 includes a rotatable output shaft 78 disposed in a centralhollow of leg 56. Output shaft 78 extends from motor 44 upwardly towardpedestal center opening 66. A gear fixed to the top of output shaft 78(gear not illustrated) engages a gear train 80 disposed in leg 56 abovethe motor 44. Gear train 80 steps down the rotational speed of the motoroutput shaft 78.

The gear train 80 has a rotatable output drive shaft 82 extending fromthe top of leg 56. Drive shaft 82 is disposed in the pedestal centeropening 66 below the top surface 60. Drive shaft 82 is tubular in shape.Drive shaft 82 is provided with two diametrically opposed slots 84 (oneshown in FIG. 2) that extend longitudinally between opposite, closedends along drive shaft 82. Slots 84 each extend radially through thecylindrical wall of tubular drive shaft 82. Each slot 84 has a parallelpair of elongate interfacing sides extending between its closed,opposite slot ends.

In some versions of the invention, motor 44 and gear train 80 arecollectively provided so that the gear train drive shaft 82 can rotateat speeds between 100 and 500 RPM. These speeds are the under loadspeeds at which the drive shaft 82 rotates during operation of the bonecleaning system 40 when bone stock is disposed in the cleaning module46. Motor output shaft 78, gear train 80, and drive shaft 82 aredescribed in greater detail in US Pat. Pub. No. 2012/0310243 A1, herebyincorporated by reference herein.

A drive spindle 86 is coupled to and driven by drive shaft 82. The drivespindle 86 includes a cylindrical stem 88. At the upper axial end ofstem 88, spindle 86 has a concentric, disc shaped head 90. Spindle head90 is circular, and may be affixed to stem 88. Alternatively, spindlehead 90 may be integrally formed with stem 88.

A number of features extend upwardly from the planar top surface of thespindle head 90. One of these features is an alignment pin 92. Thealignment pin 92 is coaxial with the longitudinal axis of the spindle 86and projects upwardly from the center of the head 90. Pin 92 iscylindrical adjacent the planar top surface of the spindle head 90.Alignment pin 92 may be formed on the axial end of stem 88 and projectthrough the center of spindle head 90. Alternatively, alignment pin 92and spindle head 90 may both be integrally formed with stem 88.Alternatively, alignment pin 92 and spindle head 90 may be integrallyformed and affixed to the axial end of stem 88. The terminal end ofalignment pin 92 is frustoconical and provided with a flattened tip.These features of alignment pin 92 are not separately numbered.

Four circumferentially and equiangularly spaced apart drive teeth 94also extend upwardly from the planar top surface of the spindle head 90.Drive teeth 94 are distributed about the perimeter of the spindle head90. Drive teeth 94 have arcuate, radially outer surfaces that are flushwith the radially outer circular edge of the spindle head 90. Driveteeth 94 also have arcuate, radially inner surfaces. Extending betweenthe radially outer and inner surfaces of each drive tooth 94 is a pairof circumferentially opposite, inwardly tapered side surfaces; thesesurfaces of drive teeth 94 are planar and perpendicular to the planartop surface of the spindle head 90, and are not separately numbered.Drive teeth 94 do not extend as far as alignment pin 92 does from theplanar top surface of spindle head 90.

Spindle 86 is dimensioned and positioned so that cylindrical stem 88 isslidably received in the coaxial, longitudinal bore of the tubular driveshaft 82. A cylindrical drive pin 96 is fitted into a cross bore (notseparately numbered) extending radially through the spindle stem 88. Theopposed ends of the drive pin 96 extend from the cylindrical surface ofstem 88, and are disposed in the diametrically opposed slots 84 formedin tubular drive shaft 82. Near its opposite ends, drive pin 96 abutsand slidably engages the circumferentially interfacing elongate sides ofthe slots 84. There is little or no relative angular movement betweenthe tubular drive shaft 82 and the coaxial stem 88. Rotation of thedrive shaft 82, induced by motor 44 through the gear train 80, isimparted to the stem 88 through the abutting engagement between drivepin 96 and the sides of slots 84.

Stem 88 and tubular drive shaft 82 have relative coaxial movement in arange limited by the length of slots 84. In this range, and relative toleg 56, stem 88 thus has an uppermost axial position which is limited byabutting engagement between drive pin 96 and the top ends of slots 84,and a lowermost axial position which is limited by abutting engagementbetween drive pin 96 and the bottom ends of slots 84. The engagementbetween slots 84 and drive pin 96 retains the drive spindle 86 to thedrive shaft 82 and transfers torque therebetween. Hence, the drivespindle 86 rotates in unison with the drive shaft 82 and is able to movelongitudinally relative to the gear train 80.

A push-button switch 98 is mounted to the base unit foot 54. The pushbutton of switch 98 is biased with a spring (not illustrated) into itsextended position, in which switch 98 is electrically open. Depressionof the push button against this spring-biased force electrically closesswitch 98. A socket 100, shown in FIG. 1, receives cable 52 from controlconsole 50 and includes terminals that are electrically connected to thecable conductors.

Internal to foot 54 is a circuit board (not illustrated) electrically inseries between socket 100 and motor 44. Mounted to the circuit board areelectrical components that function as an electric motor controller. Thefunction of the motor controller is to regulate power received at socket100 for energizing motor 44. Switch 98 is placed electrically in seriesbetween socket 100 and the circuit board. Alternatively, switch 98 isplaced electrically in series between the circuit board and motor 44.Power received from console 50 through cable 52 and socket 100 isregulated by the motor controller and provided to the windings of motor44 when switch 98 is electrically closed. Power to the motor 44 isdiscontinued when the push button is released and switch 98 electricallyopens. The specific structure and configuration of these electricalcomponents are of any suitable type well known to those of ordinaryskill in the motor control-related arts and are not illustrated.

Drive module 45 includes a shell 200. Shell 200 is dimensioned to fit tothe base unit 42 so that the base unit motor 44, when actuated, drives agear train 201 (see FIG. 5) in the drive module 45 that ultimatelydrives the cutter 48 and other components in the cleaning module 46 toclean bone stock.

Shell 200 has a bottom 208 and an outer wall 204. Outer wall 204 has anouter periphery that allows the shell 200 to be slip fitted into themounting space 64 above pedestal top surface 60 and within lip 62.

Four circumferentially and equiangularly spaced apart notches 212 extendradially inward in, and axially upward from, a downwardly directed faceof the outer wall 204 (two notches are shown in FIG. 1). Notches 212 aredimensioned so that when the shell 200 is fitted to base unit 42,pedestal teeth 70 are seated in the notches 212. Engagement of the teeth70 and notches 212 prevents unwanted rotation of the shell 200 relativeto the base unit 42 during operation.

Outer wall 204 is further provided with two additional side notches 214that are diametrically opposed from each other. Side notches 214 extendradially inwardly from an outer cylindrical surface of the outer wall204 at a location above a bottom of the outer wall 204. Moreparticularly, shell 200 is formed so that when the shell 200 is seatedin pedestal mounting space 64 and teeth 70 are seated in notches 212,side notches 214 are positioned to receive the radially inwardlydirected fingers 74 of retention arms 72.

The fingers 74 are biased radially inwardly to seat against cooperatingsurfaces of the side notches 214 to selectively lock shell 200 to baseunit 42. The upper surfaces of fingers 74 may be downwardly angledradially inwardly. This allows shell 200 to slidably engage and movefingers 74 radially outward against the biasing force acting onretention arms 72. Thus, shell 200 may be pushed downwardly past thefingers 74 and received in mounting space 64 without levers 76 beingmanually actuated.

Shell 200 further includes a base plate 215 and a top 216. Top 216 isfixed to the outer wall 204 by fasteners, ultrasonic welding, oradhesive (not illustrated). Base plate 215 is integral with the outerwall 204. Outer wall 204 extends upwardly from base plate 215 to definea lower cavity 218 of shell 200. The gear train 201 is secured to theshell 200 within the lower cavity 218.

A drive gear 226, shown in FIGS. 5 and 6, is supported to rotate withinthe shell 200. In particular, a lower portion of the drive gear 226 iscylindrical and smooth and is rotatably supported by a bearing member Bin the base plate 215 of shell 200. An upper portion of the drive gear226 is a spur gear that is cylindrical in shape. When shell 200 isreceived in mounting space 64 of pedestal 58, drive gear 226 engages thespindle head 90. Driving torque is transferred from the spindle head 90to the drive gear 226.

Drive gear 226 has a downwardly directed face with recesses havingcorresponding shapes and locations that cooperate with those of thealignment pin 92 and the drive teeth 94 protruding upwardly from the topsurface of the spindle head 90. More particularly, drive gear 226includes a centrally located alignment pin recess 246 and fourcircumferentially and equiangularly spaced apart drive tooth-receivingrecesses 248. Recesses 246 and 248 receive alignment pin 92 and driveteeth 94, respectively. The walls of each drive tooth recess 248 areparallel to the respectively interfacing surfaces of the drive tooth 94slidably received therein. Spindle head 90 and drive gear 226 thusdefine a dog clutch for transferring torque from the spindle head 90 tothe drive gear 226 when shell 200 is received in mounting space 64 ofpedestal 58, and teeth 94 and recesses 248 are mated.

The cleaning module 46 also has a cleaning module shell 250. Cleaningmodule shell 250 includes a cleaning module base 245. Cleaning modulebase 245 has a recess (not numbered) shaped to seat on a boss (notnumbered) located on the top 216 of the shell 200 of drive module 45. Anouter peripheral wall 247 is integral with the cleaning module base 245and extends upwardly from the cleaning module base 245. A top 249 isfixed about its periphery to the outer peripheral wall 247 by fasteners,ultrasonic welding, or adhesive (not illustrated).

As shown in FIG. 7, cleaning module shell 250 defines a void space 252for receiving harvested and uncleaned bone stock. During use, cutter 48cleans the bone stock in the void space 252 by cutting soft tissue andother debris from the bone stock.

Cutter 48 is located within void space 252. The cutter 48 is supportedto rotate about central axis A. The cutter 48 includes a shaving rotor260 with helical flutes 262 having cutting edges 264 (not shown forsimplicity in FIG. 6, but see FIGS. 14-16). During operation of system40, cutter 48 rotates about central axis A and the cutting edges 264clean bone stock in the void space 252 by cutting soft tissue from thebone stock. Cutter 48 rotates in a counterclockwise direction aboutcentral axis A (as viewed from above).

A shaving tube 270 extends coaxially about the cutter 48, as shown inFIGS. 6 and 7. Shaving tube 270 defines a cutter window 272 throughwhich tissue attached to the bone stock is received for engagement bythe cutter 48. The cutter window 272 is bounded by two shaver edges 274.The shaver edges 274 are sharp so as to cut soft tissue caught betweenthe shaving rotor 260 of cutter 48 and the shaving tube 270 when theshaving rotor 260 rotates relative to the shaving tube 270. The shaveredges 274 also act as impingement structures against which soft tissueabuts and is temporarily held to facilitate cutting by shaving rotor 260of cutter 48.

Shaving tube 270 is configured to make one complete rotation(approximately 360 degrees) about central axis once every 1 to 10seconds in a counterclockwise direction, or in some case, once every 1to 5 seconds. Complete rotation of the shaving tube 270 alternates withperiods of time in which the shaving tube 270 is stationary and notrotating. When rotating, shaving tube 270 rotates at about 30 to 120RPM.

Owing to the helical geometry of flutes 262, and the relatively slowrotation of shaving tube 270 compared to cutter 48, as the cutter 48rotates, cut soft tissue is augered axially upwardly along cutter 48between the cutter 48 and the shaving tube 270 to be expelled out of atop end of the shaving tube 270 (see FIG. 6). In essence, the cutter 48acts as a screw conveyor. The space between the cutter 48 and theshaving tube 270 is a debris passage through which the cut soft tissueis augered and ultimately expelled.

A lid 500 (removed in FIG. 7, but shown in FIGS. 4 and 6) is rotatablydisposed about the shaving tube 270 near the top end. The lid 500defines a collecting surface 502 onto which the tissue that exits fromthe top end of the shaving tube 270 can fall. The collecting surface 502is spaced below the top end of the shaving tube 270 to act as a debriscatch.

The lid 500 has a slide handle 504. Handle 504 extends upwardly from thelid 500 to be grasped by the user. The user can slide the lid 500 touncover an opening 506 in the cleaning module shell 250 through whichthe bone stock can be received to place the bone stock in the void space252.

A cap 508 is attached to the cleaning module shell 250 to cover andenclose the collecting surface 502. The cap 508 defines a collectingspace into which the cut soft tissue is stored for later retrieval ordisposal.

Referring to FIGS. 8-10, which show the cleaning module 46 with shell250, lid 500, and cap 508 removed, a circular tumble plate 290 isoperatively coupled to the cutter 48 to rotate with the cutter 48 at thesame speed. The bone stock sits on top of the tumble plate 290 duringcleaning so that, when actuated, the tumble plate 290 carries the bonestock to reorient the bone stock relative to the cutter 48 for moreefficient cutting of the soft tissue from the bone stock. Duringoperation of system 40, tumble plate 290 is driven to rotate aboutcentral axis A.

An upper surface 292 of the tumble plate 290 carries the bone stock. Inthe embodiment shown, the upper surface 292 is flat and smooth. In someembodiments, the upper surface 292 is textured or has gripping features(not illustrated) to grip the bone stock and facilitate moving the bonestock.

A tubular shaft 294 is fixed to the tumble plate 290, as shown in FIG.6. Tubular shaft 294 extends downwardly from the tumble plate 290. Thetubular shaft 294 is coaxially disposed about the shaving tube 270.Bearing members B are located between the tubular shaft 294 and theshaving tube 270 to facilitate smooth relative rotation between thetubular shaft 294 and the tumble plate 290. Likewise, a bearing member Bis located between tubular shaft 294 and cleaning module base 245. Aswill be described further below, the tumble plate 290 is constantlyrotating, while the shaving tube 270 periodically rotates. Bearingmembers B are shown schematically and may include bearings, bushings, orthe like.

Tumble plate 290 is disposed in a recess 243 in a top surface (notnumbered) of the cleaning module base 245 (see FIG. 6). A lower surface(not numbered) of the tumble plate 290 rides on a raised ring-shapedsection 297 of cleaning module base 245. The ring-shaped section 297(see FIG. 4) is disposed in the recess 243. Upper surface 292 of tumbleplate 290 is coplanar with the top surface of the cleaning module base245. In some embodiments, the upper surface 292 of tumble plate 290 isslightly recesses below top surface of the cleaning module base 245.Ring-shaped section 297 is formed of low friction material to facilitaterotation of the tumble plate 290 thereon. Alternatively, the tumbleplate 290 rides on bearing members (not illustrated) in the recess 243.

An arm 300 extends over the planar upper surface 292 of tumble plate290. The arm 300 may be spaced above the upper surface 292 of tumbleplate 290 to provide a small gap therebetween. The gap can be sized toprevent bone stock from passing therethrough. In other embodiments, thearm 300 rides on the upper surface 292 of tumble plate 290. The arm 300acts as a guide to direct and press the bone stock into the cutter 48through the cutter window 272 of the shaving tube 270. In the embodimentshown, the arm 300 has a jalapeno-shaped containment wall 301 thatdefines a bone stock space 302 into which the bone stock is initiallydeposited for cleaning. The bone stock space 302 moves with the arm 300as the arm 300 oscillates between engaged and disengaged positions. Thecontainment wall 301 is shaped to direct the bone stock into positionbetween the arm 300 and the cutter 48 when the arm 300 moves to anengaged position.

FIGS. 10 and 11 shows arm 300 moving to an extreme clockwise positionwithout any bone stock present in the bone stock space 302. FIG. 11Ashows arm 300 in an engaged position. In the engaged position of FIG.11A, the arm 300 is located so that bone stock is pressed into theshaving rotor 260 of cutter 48 by a press block 304 of the arm 300through the cutter window 272. Front face 306 of press block 304 acts asa bearing surface that presses bone stock into cutter window 272 andagainst the cutting edges 264.

It should be appreciated that the arm 300 moves between a plurality ofengaged positions and a plurality of disengaged positions. In essence,when the front face 306 of arm 300 is pushing bone stock into the cutter48, the arm 300 is in an engaged position, even though the rotationalposition of the arm 300 may vary as more or less bone stock is locatedbetween the front face 306 and the cutter 48. When the arm 300 islocated so that there is space between the front face 306 and cutter 48,such that the space is not being caused by bone stock trappedtherebetween, then the arm 300 is in a disengaged position, i.e., nobone stock is engaged and being pressed into the cutter 48.

In a disengaged position, the arm 300 is located so that the bone stockis released from being pressed into the cutter 48 by the press block 304so that the bone stock is provided an opportunity to be reoriented bythe tumble plate 290. The bone stock is reoriented through continuedrotation of the tumble plate 290, which, along with cutter 48, continuesto rotate when the arm 300 is in engaged or disengaged positions, ormoving therebetween. The bone stock is further reoriented by rotatingthe shaving tube 270 through one or more complete rotations aboutcentral axis A.

Front face 306 of press block 304 is configured to follow an arcuatepath (not illustrated) to the cutter 48 when moving from a disengagedposition to an engaged position. The arm 300 is shaped so that in anengaged position front face 306 faces the cutter 48 and containment wall301 corrals the bone stock into position between the front face 306 andcutter 48 so that the bone stock is trapped and pressed into the cutter48.

Arm 300 is periodically reciprocated between engaged and disengagedpositions to reorient the bone stock trapped between the arm 300 and theshaving tube 270. The arm 300 pivots between engaged and disengagedpositions about 5 to 20 times per minute. The speed at which the arm 300pivots between engaged and disengaged positions is from 5 to 20 RPM.Movement of the arm 300 may be timed to the speed/motion of the shavingtube 270 so that the arm 300 is in an engaged position when the shavingtube 270 is actuated or when the shaving tube 270 is stationary.Likewise, the arm 300 is controlled so as not to pivot during somerotations of the shaving tube 270 when the arm 300 is in a disengagedposition.

A biasing device such as a spring 278 (see FIG. 23A) biases the arm 300toward an engaged position. When bone stock is present and becomeslocated between the front face 306 and the shaving rotor 260, then thespring 278 acts to press the arm 300 into the bone stock to push thebone stock against the cutter 48. Accordingly, the pressure exerted onthe bone stock against the cutter 48 can be predetermined based on thesize and properties of the spring 278.

If the bone stock should become piled or accumulate in such a way as toovercome the bias of spring 278 the bone stock would urge the arm 300away from the cutter 48 against the bias of spring 278. The spring 278may be an extension spring that acts to rotate arm 300 about axis A5toward an engaged position. The force acting on the arm 300 via thespring 278 is transferred through the arm 300 to the bone stock. Shouldthe opposing force from the bone stock to the arm 300 increase beyondthe force of the arm 300 resulting from the spring 278, then the spring278 is extended. As a result, the force acting on the bone stock islimited.

The spring 278 is associated with the arm 300 to act as a force limitingfeature so that the force with which the arm 300 presses bone stock intothe cutter 48 can be limited. The spring 278 limits damage to theosteoblastic progenitor layer of the bone stock by keeping the forceapplied to the bone stock in a range in which the osteoblasticprogenitor layer remains substantially intact after the bone stock iscleaned. The specific force is dependent on geometry of cutter 48 andvaries as the cutter geometry varies. For instance, with cutter geometrythat more aggressively cuts material from the bone stock the force thatcould result in damage to the osteoblastic progenitor layer is less thanwith a cutter geometry that less aggressively cuts material from thebone stock. Thus, the force is tuned to the cutter geometry and isdetermined by identifying the force at which the osteoblastic progenitorlayer remains substantially intact, but which still substantially cleansthe bone stock.

When front face 306 engages or is at least in close proximity to shavingtube 270, but after some amount of bone cleaning takes place, shavingtube 270 may be rotated about central axis A to dislodge bone stocktrapped therein. Arcuate side faces 307, 309 of press block 304 providebearing surfaces against which trapped bone stock can bear as it isloosened or dislodged from cutter 48 and/or shaving tube 270 when theshaving tube 270 rotates.

Referring specifically to FIG. 11, the arcuate side faces 307, 309 ofpress block 304 abut corresponding side faces 275, 277 of the shavingtube 270 when the arm 300 is in an extreme clockwise position and nobone stock is present in the bone stock space 302 between the front face306 and shaving rotor 260. The faces 307, 309, 275, 277 are shaped forabutting contact to prevent the front face 306 from intruding on thecutter 48 and to maintain a gap or spacing between the front face 306and the cutter 48.

Arm 300 is shown separately in FIGS. 12 and 13. As shown, press block304 protrudes inwardly from inner surface 308 of containment wall 301.Inner surface 308 defines the bone stock space 302. Front face 306 ofpress block 304 is arcuate in shape and interconnects arcuately shapedside surfaces 307, 309. Press block 304 has an upper surface 310 that isspaced below a top surface 312 of arm 300 (see FIG. 12). Press block 304has a lower surface 314 that is coplanar with a bottom surface 316 ofarm 300 (see FIG. 13).

Arm 300 includes a hub 318 pivotally mounted to cleaning module shell250 about a hub pivot pin H (see FIG. 4) that is mounted to cleaningmodule top 249. Hub 318 is supported for pivotal movement about axis A5to move arm 300 between disengaged and engaged positions. When thecleaning module 46 is positioned on top of the drive module 45, aninterface tab 320 is positioned to be engaged by the gear train 201 soas to move the arm 300 between engaged and disengaged positions asdescribed further below. The hub 318 has a semi-cylindrical or arcuateouter surface 324 defined between the top and bottom surfaces 312, 316of arm 300. The arm 300 further includes wing walls 326, 328 connectedto hub 318 and extending divergently from hub 318 to containment wall301 to interconnect the hub 318 and the containment wall 301.

As shown in FIGS. 14-16, cutter 48 has a cylindrical intermediate shaft251 extending downwardly from the shaving rotor 260. A bearing member B(see FIGS. 4 and 6) is located about intermediate shaft 251 to centerintermediate shaft 251 and support rotation of the cutter 48 withshaving tube 270.

An axially lower stub shaft 254 with a non-circular cross sectionextends downwardly from the intermediate shaft 251. The lower stub shaft254 is shaped to fit within a correspondingly shaped axial bore 255 inan axially upper section of drive gear 226. Owing to the non-circulargeometry of the cross sections of lower stub shaft 254 and its receivingbore in drive gear 226, the cutter 48 and drive gear 226 are angularlyfixed about central axis A for rotation together when engaged. Whenoperating, the cutter 48 and drive gear 226 constantly rotate from 100to 500 RPM.

Lower stub shaft 254 extends downwardly from intermediate shaft 251 to achamfer 370. Lower stub shaft 254 is smooth and generallysemi-cylindrical between opposing flats 256, which define thenon-circular geometry of the cross-section.

The shaving rotor 260 of the cutter 48 is located axially above theintermediate shaft 251. The shaving rotor 260 is generally cylindricaland has an outer diameter that is larger than the diameters of theintermediate shaft 251 and lower stub shaft 254. The shaving rotor 260,intermediate shaft 251, and lower stub shaft 254 are integrally formedof metal, such as stainless steel.

A plurality of flutes 262 and corresponding cutting edges 264 aredefined on shaving rotor 260. Upper 362 and lower 364 axial ends ofshaving rotor 260 are flat and lie in planes perpendicular to centralaxis A. Flutes 262 and cutting edges 264 extend between the ends 362,364. The flutes 262 and cutting edges 264 are arranged such that theyhelically wrap about shaving rotor 260 between ends 362, 364 and have ahelix angle of from 20 to 70 degrees, or in some embodiments, from 30 to60 degrees. In the embodiment shown, the cutter 48 has a helix angle of60 degrees. An outside diameter of the shaving rotor 260 is ⅝ inches.The cutting edges 264 each have a rake angle of between −10 and 10degrees. In the embodiment shown, the cutting edges 264 have a rakeangle of 0 degrees. Ten flutes 262 are present in the cutter 48 shown inFIGS. 14-16.

Alternative embodiments of the cutter 48 are shown in FIGS. 14A-16A and14B-16B. In FIGS. 14A-16A, the cutter 48A has a helix angle of 30degrees. An outside diameter of the shaving rotor 260A is ⅝ inches. Thecutting edges 264A have a rake angle of 0 degrees. Ten flutes 262A arepresent in the cutter 48A shown in FIGS. 14A-16A. In FIGS. 14B-16B, thecutter 48B has a helix angle of 45 degrees. An outside diameter of theshaving rotor 260B is ⅝ inches. The cutting edges 264B have a rake angleof 0 degrees. Ten flutes 262B are present in the cutter 48B shown inFIGS. 14B-16B.

Referring to FIGS. 17 and 18, shaving tube 270 is generally cylindricaland tubular for fitting over cutter 48. As shown in FIG. 17, the cutterwindow 272 creates the sharp shaver edges 274 capable of cutting softtissue. A shaver edge 274 is located on both sides of the cutter window272. Thus, the shaver edges 274 further define the sides of the cutterwindow 272. Surfaces 280, 282 at the top and bottom of the cutter window272 are generally flat and parallel. A smooth shaft section 286 of theshaving tube 270 is located below the cutter window 272. The smoothshaft section 286 extends downwardly to a bottom end 276.

Shaver edges 274 are located so that soft tissue trapped between shavingrotor 260 and an inner cylindrical surface 284 of shaving tube 270 iscut by the shaver edges 274 either by action of the cutter 48 rotatingrelative to the shaving tube 270 when the shaving tube 270 is stationaryor when the shaving tube 270 is rotating.

Tumble plate 290 is shown in FIGS. 19 and 20. The tumble plate 290 isgenerally circular and flat. Tubular shaft 294 is fixed to a bottomsurface (not numbered) of tumble plate 290. The tubular shaft 294extends downwardly from the tumble plate 290 and terminates in a gearsection 296. A cylindrical passage 298 passes through the tumble plate290, tubular shaft 294, and gear section 296. As shown in FIG. 6, thecylindrical passage 298 is sized to accommodate the shaving tube 270,cutter 48, and bearing member B. In the embodiment shown, the bearingmember B is a bushing press fit into the shaving tube 270 to rotatetherewith. Gear section 296 is operatively coupled to the drive gear 226when the cleaning module 46 is fitted onto the drive module 45 andconnected thereto.

Referring to FIGS. 21 and 22, when the cleaning module 46 is connectedto the drive module 45, the gear train 201 of drive module 45 is capableof transferring torque received from base unit motor 44 to the cutter48, shaving tube 270, tumble plate 290, and arm 300 of the cleaningmodule 46. In the embodiment shown, the cleaning module 46 is providedas a disposable unit designed to be utilized for one bone cleaningsession and then discarded, while the drive module 45 is provided as areusable unit designed to be sterilized and reused.

Referring to FIGS. 22-26, gear train 201 is located in the lower cavity218 of shell 200. The gear train 201 includes the drive gear 226. Whenshell 200 is received in mounting space 64 of pedestal 58, drive gear226 engages the spindle head 90. Driving torque is transferred from thespindle head 90 to the drive gear 226 upon actuation of the base unitmotor 44.

When the cleaning module 46 is connected to the drive module 45, severalconnections are made. In one such connection, the lower stub shaft 254of cutter 48 is inserted into the correspondingly shaped axial bore 255of drive gear 226. In another connection, the gear section 296 oftubular shaft 294, which is fixed to the tumble plate 290, engages acoupler gear 401 (see FIG. 6). The coupler gear 401 includes a lowerspur gear 402 directly driven by drive gear 226 that also engages anddrives the gear section 296. These connections establish an operativecoupling between the base unit motor 44 and cutter 48/tumble plate 290such that when the base unit motor 44 is actuated, drive gear 226rotates cutter 48 and tumble plate 290 in unison about central axis A.

An upper spur gear 404 of coupler gear 401 is centrally fixed to thelower spur gear 402 to rotate therewith about the same central axis A2,which is fixed relative to the shell 200. Thus, when the lower spur gear402 is driven by the drive gear 226, the upper spur gear 404, albeit ofsmaller diameter, is likewise driven.

A speed reducing gear 406 engages the upper spur gear 404 to be driventhereby. The speed reducing gear 406 has a lower spur gear 408 and anupper spur gear 410 of smaller diameter. The upper spur gear 410 ofspeed reducing gear 406 is centrally fixed to the lower spur gear 408 ofspeed reducing gear 406 to rotate therewith about the same central axisA3, which is fixed relative to the shell 200.

A cam gear 412 engages the speed reducing gear 406 so that rotation ofthe speed reducing gear 406 results in rotation of the cam gear 412. Thecam gear 412 has a cam spur gear 414 that engages the upper spur gear410 of speed reducing gear 406 to be driven by the upper spur gear 410.The speed reducing gear 406 reduces the rotational speed input fromcoupler gear 401.

Cam gear 412 includes a cam plate 416 having a non-circular, cam-shaped,perimeter. The perimeter has a cam outer surface 418 perpendicular tothe cam spur gear 414. The cam plate 416, when viewed from above, has asemi-circular section 420 joined by a cam section 422 (see FIG. 24). Thecam section 422 protrudes radially outwardly from a cam gear axis A4further than the semi-circular section 420 (see FIG. 24). The cam gearaxis A4 is fixed relative to the shell 200.

When cam spur gear 414 is driven by the upper spur gear 410 of speedreducing gear 406, cam spur gear 414 rotates about cam gear axis A4.Owing to being fixed to the cam spur gear 414, cam plate 416 likewiserotates.

A cam follower 426 couples the arm 300 to the gear train 201. Camfollower 426 has a generally cylindrical body (not numbered) with upperand lower surfaces (not numbered). A post 428 is integrally formed withthe body and extends downwardly from the lower surface. Post 428 isconfigured to generally follow along the cam outer surface 418 (althoughnot shown, the post 428 may include an outer bearing that rolls alongthe cam outer surface 418).

A second post 429 is integrally formed with the body and extendsdownwardly from the lower surface at a location spaced from the post428. Both posts 428, 429 are spaced radially outwardly from axis A5(also referred to as cam follower axis A5). One end of spring 278 isattached to the second post 429. The other end of spring 278 is mountedto an inner surface of outer wall 204 of shell 200 so that the spring278 (in this case an extension spring) is constantly biasing the camfollower 426 clockwise (viewed from above).

The cam follower 426 also has a cam interface tab 430 configured toengage hub interface tab 320, as shown in FIG. 23A (shown without hubpivot pin H). The cam interface tab 430 is part of the drive module 45,while the hub interface tab 320 is part of the cleaning module 46. Thecam interface tab 430 has a first side surface S1 and a second sidesurface S2. The first side surface S1 is configured to abut a third sidesurface S3 of hub interface tab 320. When the first and third sidesurfaces S1, S3 abut, the first and third side surfaces S1, S3 areparallel to one another.

A torsion spring 435 is seated within a bore 437 located in the hub 318.Torsion spring 435 has two tangs 439 a, 439 b. Tang 439 a abuts secondside surface S2 of cam interface tab 430 upon connection of cleaningmodule 46 to drive module 45. Tang 439 b abuts an inner surface 327 ofwing wall 328. Thus, torsion spring 435 acts to urge arm 300counterclockwise relative to cam follower 426.

FIGS. 23B through 23E show movement of the cam plate 416 andcorresponding movement of the cam follower 426. FIG. 23B shows the caminterface tab 430 engaging the hub interface tab 320 and together thearm 300 and cam follower 426 are biased into an extreme clockwiseposition under the tension of spring 278. Post 428 is contacting thesemi-circular section 420 of the cam plate 416. This positionalconfiguration occurs when no bone stock is trapped between the frontface 306 and cutter 48, i.e., no bone stock is being cleaned.

In FIG. 23C, as the cam plate 416 rotates, the post 428 moves to the camsection 422 of cam plate 416 from the semi-circular section 420, therebyrotating the cam follower 426 counterclockwise (viewed from above).Since the cam section 422 extends radially further away from the camgear axis A4 than the semi-circular section 420, the cam follower 426 isrotated counterclockwise about the cam follower axis A5. The camfollower axis A5 is fixed relative to the shell 200.

When this movement of the cam follower 426 occurs, the tang 439 a oftorsion spring 435 is wound toward the tang 439 b. The arm 300 is thusurged to follow the movement of the cam follower 426 via the tang 439 b,but FIG. 23C shows a delayed reaction of the arm 300, which results in agap forming between the first and third side surfaces S1, S3. Thisdelayed reaction can either be from slow reaction of the torsion spring435 or perhaps bone stock is trapped between the arm 300 and shavingtube 270 preventing counterclockwise rotation of the arm 300.

FIG. 23D shows the arm 300 rotationally catching up with the camfollower 426 under the torque created by torsion spring 435 resulting inthe third side surface S3 abutting the first side surface S1. The arm300 is thus moved to disengaged positions via the torsion spring 435.The torsion spring 435 acts to bias arm 300 counterclockwise such thatcontainment wall 301 engages the shaving tube 270. Accordingly, thecontainment wall 301 can act as a bearing surface to loosen materialwhen the shaving tube 270 rotates. In FIG. 23D, the post 428 continuesto follow along the cam section 422 of the cam plate 416. In FIGS. 23Cand 23D, the spring 278 acts to bias the post 428 of the cam follower426 against the outer surface 418 of the cam plate 416 when the post 428follows around the cam section 422 of the cam gear 412. The spring 278is extended in these positions compared to the extension of spring 278in FIG. 23B.

FIG. 23E shows the cam plate 416 rotating back to a position in whichthe semi-circular section 420 is adjacent to the post 428. When thisoccurs, if there was no bone stock between the front face 306 and thecutter 48 the arm 300 would move to the fully clockwise position underthe bias of spring 278, which would also rotate the cam follower 426clockwise such that the post 428 contacted the outer surface 418 of thecam plate 416 on the semi-circular section 420. However, FIG. 23Edepicts a typical cleaning situation in which bone stock is trappedbetween the front face 306 and the cutter 48 and is being cleaned by thecutter (see FIG. 11A). Thus, the arm 300 is impeded by the bone stock,which opposes the force provided by spring 278. As a result, the arm 300is unable to rotate completely into the fully clockwise positionabutting shaving tube 270. Instead, the arm 300 is in an engagedposition in which the trapped bone stock is being pressed into thecutter 48. The trapped bone stock causes the arm 300 to be spaced fromthe shaving tube 270 and cutter 48. Owing to the abutting first andthird surfaces S1 and S3, cam follower 426 is also not allowed to fullyrotate clockwise such that the post 428 is spaced from (or lifted off)the outer surface 418 of the cam plate 416.

Cam follower 426 and hub 318 of arm 300 pivot about cam follower axisA5, as shown in FIG. 23F. A bearing member B may be located between thecam follower 426 and top 216 of shell 200 to allow rotation of the camfollower 426 in the top 216. Similarly, a bearing member B is locatedbetween hub 318 and cleaning module base 245 to allow rotation of hub318 in the cleaning module base 245. When the cleaning module 46 isplaced on the drive module 45, the hub pivot pin H centers into acentral bore (not numbered) in the cam follower 426 to align the camfollower 426 to the hub 318.

Referring back to FIG. 22, an indexing gear 432 is disposed for rotationabout indexing central axis A6 in shell 200. The indexing central axisA6 is fixed relative to shell 200. The indexing gear 432 includes anindexer spur gear 434. An indexing plate 436 is fixed to an uppersurface of the indexer spur gear 434. The indexing plate 436 defines aplurality of indexing grooves 438. Four indexing grooves 438 areprovided in the embodiment shown. The indexing grooves 438 are equallycircumferentially located every 90 degrees about the indexing centralaxis A6. Indexing grooves 438 start at a position spaced from indexingcentral axis A6, are elongated in a radial direction therefrom, andterminate short of outer perimeter of indexer spur gear 434.

An indexer pin 440 depends downwardly from a bottom surface of cam spurgear 414 (see FIG. 25). The indexer pin 440 is spaced radially inwardlyfrom a perimeter of the cam spur gear 414, yet radially outwardly fromthe cam gear axis A4. When cam spur gear 414 is driven, indexer pin 440rotates about cam gear axis A4. The indexer pin 440 is configured toengage the indexing plate 436 and slide into the indexing grooves 438.For every one rotation of the cam spur gear 414, the indexer pin 440engages one indexing groove 438 and rotates the indexing gear 432one-quarter of a turn or 90 degrees about indexing central axis A6. Thisarrangement is conventionally referred to as a geneva drive in which thecam spur gear 414 is a drive wheel and the indexing gear 432 is a drivenwheel. A blocking disc 439 of this geneva drive is shown in FIG. 25. Theblocking disc 439 locks the driven wheel in position between steps.

A tube gear 442 engages the indexer spur gear 434 to be driven therebyabout tube gear axis A7. The tube gear 442 has a lower spur gear 444 andan upper spur gear 446 of smaller diameter. The upper spur gear 446 iscentrally fixed to the lower spur gear 444 to rotate therewith about thesame tube gear axis A7, which is fixed relative to the shell 200. Theupper spur gear 446 engages the indexer spur gear 434 to be periodicallydriven by the indexer spur gear 434, as dictated by the geneva drive.Lower spur gear 444 engages ring-shaped spur gear 448.

The bottom end 276 of shaving tube 270 is press-fit into the ring-shapedspur gear 448 to rotate with rotation of the ring-shaped spur gear 448.The ring-shaped spur gear 448 is thus part of the cleaning module 46 inthe embodiment shown. In other embodiments, the ring-shaped spur gear448 forms part of the drive module 45.

Ring-shaped spur gear 448 is rotatable relative to the drive gear 226about central axis A. In another connection made when the cleaningmodule 46 is mounted to the drive module 45, the ring-shaped spur gear448 engages lower spur gear 444. The tube gear 442 is configured so thatone quarter turn of the indexer spur gear 434 results in one completerotation of 360 degrees of the ring-shaped spur gear 448 and shavingtube 270.

Pivot pins P having heads and threaded ends are used to secure thecoupler gear 401, speed reducing gear 406, cam gear 412, indexing gear432, and tube gear 442 to the shell 200 of drive module 45. In theembodiment shown top 216 of shell 200 includes internally threadedbosses to which the pivot pins are attached (see, e.g., FIG. 6). Asimilar boss is located on cleaning module top 249 to receive hub pivotpin H (pivot pin with threaded end, but without head) for rotatablysupporting the hub 318. Spacers S may be provided about pivot pins P tospace certain gears from top 216 as appropriate (see FIG. 6). The gears401, 406, 412, 432, 442, cam follower 426, and hub 318 are configured torotate about the pins P, H, which define axes A2-A7. These axes A2-A7are also fixed in relation to each other and parallel to one another.

II. Operation

During operation, uncleaned bone is first placed in the void space252/bone stock space 302 for cleaning and the lid 500 is then rotatedinto place relative to cleaning module shell 250 via slide handle 504 tocover the void space 252. The uncleaned bone includes soft tissueattached thereto that requires removal without damaging the periosteumlayer.

The cleaning module 46 is then fitted to the drive module 45, after thedrive module 45 is releasably locked to the base unit 42. In someembodiments, the uncleaned bone is placed in the void space 252/bonestock space 302 after these steps.

The surgical personnel actuate the cleaning module 46 by depressing thepush button of base unit switch 98. In response to the depression ofswitch 98 the motor controller (not illustrated) causes power to beapplied to the motor 44, which energizes the motor 44 and causes itsoutput shaft 78 to turn in a direction that drives rotation of cutter 48counterclockwise as viewed from above.

The tumble plate 290 rotates in unison with the cutter 48 in thecounterclockwise direction. Tumble plate 290 operates to move the bonestock so that the bone stock is ultimately positioned between the frontface 306 of press block 304 and cutter 48. In the engaged position,front face 306 presses the bone stock toward shaving rotor 260 of cutter48 through window 272 in shaving tube 270 to cut soft tissue from thebone stock.

The cutting edges 264 of shaving rotor 260 and/or shaver edges 274 ofshaving tube 270 cut away soft tissue from bone. The cut soft tissue andother debris is then augered upwardly between the shaving rotor 260 andshaving tube 270. The augered tissue is stored for later retrieval ordisposal. This provides a separation of soft tissue and other debrisfrom the remaining bone of the bone stock.

After some amount of bone cleaning takes place, gear train 201 isconfigured to rotate shaving tube 270 about central axis A to dislodgebone stock trapped therein. The arm 300 provides a bearing surfaceagainst which trapped bone stock can bear as it is loosened or dislodgedfrom cutter 48 and/or shaving tube 270 when the shaving tube 270rotates—with the arm 300 in either engaged or disengaged positions, andsometimes when the arm 300 is in an extreme counterclockwise position(see FIG. 23D). The gear train 201 is configured so that the shavingtube 270 rotates about central axis A between 0 and 360 degrees onceevery 1 to 5 seconds with alternating periods without rotation in whicharm 300 is actively pressing bone stock into cutter 48 through thewindow 272.

During cleaning, gear train 201 periodically pivots arm 300 between theengaged and disengaged positions to reorient the bone stock trappedbetween the arm 300 and the cutter 48/shaving tube 270. The arm 300pivots between the engaged and disengaged positions about 5 to 20 timesper minute. This further facilitates removal of soft tissue and debrisfrom all surfaces of the bone stock.

Once the cleaning module 46 has sufficiently removed soft tissue fromthe bone, the bone is removed from the cleaning module 46. In oneembodiment, the lid 500 is rotated by slide handle 504 to expose opening506. Next, the cleaned bone is grabbed by forceps or other device (notillustrated) to be placed in a collection tray for further processing.In other embodiments, not shown, the bone is gathered automatically intothe collection tray (not illustrated), which is then removed from thedrive module 45 or the cleaning module 46—depending on which module isused to hold the collection tray.

At the conclusion of the cleaning process, the cleaning module 46 isremoved from the drive module 45. Drive module 45 is also released frombase unit 42. The cleaning module 46 may then be discarded (or cleanedin some embodiments). The drive module 45 and base unit 42 are thencleaned for reuse.

One advantage of the system 40 is that it provides a mechanized andautomated manner of cleaning the bone stock that substantially reducesthe need for surgical personnel to grasp and clean the bone manually.

Likewise it should be understood that while this invention is intendedfor use to clean autograft bone, its applications are not so limited.System 40 of this invention may also be used to clean donor bone,sometimes referred to as allograft bone, or to clean or process othermaterials.

III. Alternative Embodiments

In some embodiments, the components of the drive module 45 areintegrated into the base unit 42. In these embodiments, the cleaningmodule 46 connects directly to the base unit 42. In yet otherembodiments, the components of the drive module 45 are integrated intothe cleaning module so that the gear train 201 forms part of thecleaning module.

In some embodiments, rotation of the shaving tube 270 occurs inalternating clockwise and counterclockwise directions. Oscillatingmovement of the shaving tube 270 helps to dislodge and release bonestock caught between the shaving rotor 260 and shaving tube 270. In yetother embodiments, the shaving tube 270 may be rotated less than 360degrees, such as from 90 to 270 degrees. Further, constant or periodicoscillation of shaving tube 270 about central axis A could be employed.Alternatively, constant rotation of shaving tube 270 in the samedirection could be employed to dislodge trapped bone stock. The drivemodule 45 can be configured for any of these scenarios, or anycombination thereof.

In some embodiments, when arm 300 is in the engaged position, but aftersome amount of bone cleaning takes place, shaving tube 270 may berotated completely about central axis A to dislodge bone stock trappedtherein. In other embodiments, when the arm 300 is in the extremecounterclockwise position (see FIG. 23D), a projection (not illustrated)on inner surface 308 of arm 300, opposite the press block 304, providesa bearing surface against which trapped bone stock can bear as it isloosened or dislodged from cutter 48 and/or shaving tube 270 when theshaving tube 270 rotates.

The materials from which the components of this invention are fabricatedand the geometry of the components may be different from what has beendescribed. For example, in embodiments of the invention havingcomponents intended to be disposable, some or all of those componentsmay be made of sterilizable plastic instead of being made of metal. Incertain embodiments, the cutter 48, shaving tube 270, bearing members B,and gears are formed of metal such as stainless steel, while the shells200, 250, tumble plate 290, and arm 300 are formed of sterilizableplastic. In some embodiments the gears are also formed of sterilizableplastic. In some embodiments the cutter 48 and shaving tube 270 are alsoformed of sterilizable plastic.

It is envisioned that in another alternative embodiment, the drivemodule 45 includes a separate, reversible stepper or servo motor (notillustrated) mounted to the shell 200 that directly drives the drivegear 226, and the required controls are mounted to the shell 200.Accordingly, the drive module 45 does not require mounting to the baseunit 42.

It is further envisioned that in alternative embodiments, the gear train201 includes a separate reversible stepper or servo motor (notillustrated) mounted to shell 200 that directly drives the arm 300,separately from the cutter 48, shaving tube 270, and tumble plate 290.This motor includes an output shaft connected directly to the hub 318.In this embodiment, the force limiting feature that limits damage to theosteoblastic progenitor layer is integrated in the control unit to thearm motor. More particularly, force is limited by sensing motor currentand adjusting motor voltage to maintain motor current below apredetermined set point corresponding to a given torque. The selectedtorque is determined based on the relationship between torque and damageto the osteoblastic progenitor layer. The selected torque removesunwanted material from the bone stock yet substantially maintains theosteoblastic progenitor layer.

Power may be supplied to the base unit motor 44, in some embodiments, bya battery powered control unit (not illustrated). The battery poweredcontrol unit supplies electrical energization signals to the base unitmotor 44 to actuate the base unit motor 44. The battery powered controlunit is integrated into the base unit 42. Additionally, power receivedfrom console 50 through cable 52 and socket 100 or from the batterypowered control unit is regulated by the motor controller and providedto the windings of base unit motor 44 when switch 98 is electricallyclosed. Power to the base unit motor 44 may be provided continuouslywhen the push button is actuated, and then discontinued when the pushbutton 98 is actuated a second time, or power may be provided for apredetermined period of time such as 2 minutes after actuation of thepush button 98. Alternatively, the push button 98 may be a rocker switchhaving on and off positions.

In some embodiments, flutes on the cutter have shapes other thanhelical, such as vertical flutes. Additionally, the cutter may have lessflutes or more flutes. The flutes may have a larger or smaller helixangle. The cutter may also have cutting edges with a larger or smallerrake angle.

In some embodiments, the shaver edges may be blunt so as to provideimpingement to sever soft tissue caught between the shaving rotor 260 ofcutter 48 and the shaving tube when the shaving rotor 260 rotatesrelative to the shaving tube.

IV. Alternative Cleaning Module

Referring to FIGS. 29-50, an alternative cleaning module 1046 is shown.Alternative cleaning module 1046 includes a shell 1200. Shell 1200 isdimensioned to fit to the base unit 42 so that the base unit motor 44,when actuated, drives cutter 1048. Shell 1200 defines a void space 1202for receiving harvested and uncleaned bone stock. During use, cutter1048 cleans the bone stock in the shell void space 1202 by cutting softtissue and other debris from the bone stock.

Shell 1200 has a base 1208. Shell base 1208 includes a lower wall 1210.Shell base lower wall 1210 has an outer periphery that allows the shell1200 to be slip fitted into the void space 164 above pedestal topsurface 60 and within lip 62. Shell base lower wall 1210 is coterminouswith lip 62 on both sides of notch 68 so that shell base lower wall 1210is semi-cylindrical.

Four circumferentially and equiangularly spaced apart notches 1212extend radially inward in, and axially upward from, a downwardlydirected face of the base lower wall 1210 (only one notch is shown inFIGS. 31 and 32). Notches 1212 are dimensioned so that when the shell1200 is fitted to base unit 42, pedestal teeth 70 are seated in thenotches 1212. Engagement of the teeth 70 and notches 1212 preventsunwanted rotation of the shell base 1208 relative to the base unit 42during operation.

Shell base lower wall 1210 is further provided with two additional sidenotches 1214 (see FIG. 29) that are diametrically opposed from eachother. Side notches 1214 extend radially inwardly from an outercylindrical surface of the base lower wall 1210 at a location above thebottom of the base lower wall 1210. More particularly, shell 1200 isformed so that when the shell 1200 is seated in pedestal void space 64and teeth 70 are seated in notches 1212, side notches 1214 arepositioned to receive the radially inwardly directed fingers 74 ofretention arms 72. The fingers 74 are biased radially inwardly to seatagainst cooperating surfaces of the side notches 1214 to selectivelylock shell 1200 to base unit 42. The upper surfaces of fingers 74 may bedownwardly angled radially inwardly. This allows shell 1200 to slidablyengage and move fingers 74 radially outward against the biasing forceacting on retention arms 72. Thus, shell 1200 may be pushed downwardlypast the fingers 74 and received in void space 64 without levers 76being manually actuated.

Shell base 1208 further includes a base plate 1216 mounted to base lowerwall 1210. Shell base lower wall 1210 extends downwardly from base plate1216 to define a lower cavity 1218 of shell 1200. Shell lower cavity1218 has a diameter that is larger than the diameter of spindle head 90.This allows the spindle head 90 to be received in the lower cavity 1218.

A center opening 1220 is defined in and through the base plate 1216. Asupport tube 1222 is mounted to the base plate 1216 and has an upper endthat is received in center opening 1220. A lower end of support tube1222 projects into lower cavity 1218. The support tube 1222 includes aflange 1224 located between the upper and lower ends of the support tube1222. Flange 1224 is fixed to the bottom surface of the base plate 1216by welding, fasteners (not illustrated), ultrasonic welding, adhesive,or the like.

A coupler shaft 1226 is supported to rotate within the support tube1222. Bearings 1228 are positioned inside support tube 1222 to rotatablysupport the coupler shaft 1226. The coupler shaft 1226 is tubular inshape and has an axially upper section and an axially lower section,which are separated by an axially intermediate section (sections notnumbered). Bearings 1228 are disposed about the upper and lowersections. Upper and lower sections have a common diameter. The diameterof intermediate section is relatively larger than that of upper andlower sections. Owing to its larger diameter, intermediate sectiondefines opposing annular shoulders by which the bearings 1228 areaxially spaced and against which they respectively abut.

An annular groove (not separately numbered) is formed in an innercylindrical surface of the support tube 1222. Groove is located near butaxially spaced from the lower end of the support tube 1222. A retainingring 1242 is seated in the groove and projects radially inwardly fromthe tube's cylindrical wall. The lowermost bearing 1228 axially abutsretaining ring 1242 which limits the downward movement of that bearing1228 and coupler shaft 1226 within support tube 1222. Thus, the bearings1228 and the coupler shaft 1226 are supported within the support tube1222. Retaining ring 1242 may, for example, be a circumferentially splitring of known type.

During assembly of shell 1200, bearings 1228 and coupler shaft 1226 arefirst assembled and then positioned in the support tube 1222. Once inplace, the retaining ring 1242 is seated in the groove 1240 to axiallysupport the bearings 11228 and coupler shaft 1226 within support tube1222. The coupler shaft 1226 is thus supported by the bearings 1228 forrotation relative to the support tube 1222 during operation of bonecleaning system 1040.

A receiver head 1244 is located at a lower end of the coupler shaft 1226below retaining ring 1242. The receiver head 1244 is mounted androtatably fixed to the axially lower end of coupler shaft 1226. Receiverhead 1244 can be mounted to the coupler shaft 1226 by being threaded orwelded thereto, or by another suitable means facilitating their rotatingin unison. When shell 1200 is received in void space 64 of pedestal 58,receiver head 1244 engages the spindle head 90. Driving torque istransferred from the spindle head 90 to the coupler shaft 1226 throughthe receiver head 1244.

Receiver head 1244 has a downwardly directed face with recesses havingcorresponding shapes and locations that cooperate with those of thealignment pin 92 and the drive teeth 94 protruding upwardly from the topsurface of the spindle head 90. More particularly, receiver head 1244includes a centrally located alignment pin recess 1246 and fourcircumferentially and equiangularly spaced apart drive tooth-receivingrecesses 1248. Recesses 1246, 1248 mate with alignment pin 92 and driveteeth 94, respectively. The walls of each drive tooth recess 1248 areparallel to the respectively interfacing surfaces of the drive tooth 94slidably received therein. Spindle head 90 and receiver head 1244 thusdefine a dog clutch for transferring torque from the spindle head 90 tothe receiver head 1244 when shell 1200 is received in void space 64 ofpedestal 58, and teeth 94 and recesses 1248 are mated. In the embodimentshown, the spindle 90 can be raised as needed to mate with the receiverhead 1244.

Shell 1200 includes a containment ring 1250 that is mounted to the baseplate 1216. Containment ring 1250 has a semi-cylindrical wall with anouter diameter coincident with the outer diameter of base lower wall1210. Containment ring 1250 extends upwardly from the base plate 1216.Containment ring 1250 has an inner semi-cylindrical surface 1252 thatpartially defines the shell void space 1202. The semi-cylindricalsurface 1252 of containment ring 1250 is coaxial with central axis A10of shell 1200.

Cutter 1048 is located within shell void space 1202. The cutter 1048 issupported by shell base 1208 to rotate about shell central axis A10. Thecutter 1048 has an axially lower stub shaft 1254 with a D-shaped crosssection that fits within a cooperating D-shaped axial bore (notseparately numbered) in the axially upper section of tubular couplershaft 1226. The lower stub shaft 1254 of cutter 1048 has one flat 1256that forms its D-shaped cross section. Owing to the non-circulargeometry of the D-shaped cross sections of lower stub shaft 1254 and itsreceiving bore in coupler shaft 1226, the cutter 1048 and coupler shaft1226 are angularly fixed about axis A10 for rotation together. Thecutter 1048 and coupler shaft 1226 rotate from 100 to 500 RPM.

Cutter 1048 also has an axially upper stub shaft 1258. A shaving rotor1260 of the cutter 1048 is located axially intermediate the lower 1254and upper 1258 stub shafts. The shaving rotor 1260 is generallycylindrical and has an outer diameter that is larger than the diametersof the lower 1254 and upper 1258 stub shafts. The shaving rotor 1260,upper stub shaft 1258, and lower stub shaft 1254 are integrally formed.

Shaving rotor 1260 includes helical flutes 1262 having cutting edges1264. During operation of system 1040, cutter 48 rotates about thecentral axis A10 and the cutting edges 1264 clean bone stock in theshell void space 1202 by cutting soft tissue from the bone stock. Cutter1048 rotates in a counterclockwise direction about axis A10 (as viewedfrom above).

A shaving tube 1270 extends coaxially about the shaving rotor 1260 ofcutter 1048. Shaving tube 1270 defines a pair of diametrically opposedcutter windows 1272 through which tissue attached to the bone stock isreceived for engagement by the cutter 1048. Each cutter window 1272 isbounded by at least one shaver edge 1274. The shaver edges 1274 aresharp so as to cut soft tissue caught between the shaving rotor 1260 ofcutter 1048 and the shaving tube 1270 when the shaving rotor 1260rotates relative to the shaving tube 1270. The shaver edges 1274 alsoact as impingement structures against which soft tissue abuts and istemporarily held to facilitate cutting by shaving rotor 1260 of cutter1048.

Bearing 1276 is located between upper stub shaft 1258 of cutter 1048 andshaving tube 1270. Another bearing 1278 is located between lower stubshaft 1254 of cutter 1048 and the shaving tube 1270. Bearings 1276, 1278allow for relative rotation between the shaving tube 1270 and the cutter1048.

In the embodiment shown, shaving tube 1270 is rotated about axis A10 bya drive belt 1280. Shaving tube 1270 has a driven pulley 1282 integratedinto shaving tube upper end. A belt drive shaft 1284 is journaled in thebase plate 1216 by a bearing 1286. A belt driving pulley 1288 iscoaxially mounted on upper end of belt drive shaft 1284. The drive belt1280 is taughtly disposed around driven pulley 1282 and driving pulley1288. Shaving tube 1270 is rotated about axis A10 via the drive belt1280 when the belt drive shaft 1284 is actuated.

A drive assembly 1400 actuates the belt drive shaft 1284. The driveassembly 1400 includes the receiver head 1244 and a gear train 1402.Receiver head 1244 acts as a torque input for the gear train 1402 of thedrive assembly 1400. More particularly, the receiver head 1244 transferstorque from the drive spindle 86 to the gear train 1402. In certainembodiments, the receiver head 1244 has outer gear teeth (notillustrated). The gear train 1402 operatively interconnects the gearteeth of receiver head 1244 to belt drive shaft 1284 to transfer torquefrom the receiver head 1244 to the belt drive shaft 1284.

The gear train 1402 is configured so that the shaving tube 1270 rotatesabout axis A10 between 0 and 360 degrees once every 1 to 5 seconds andin alternating clockwise and counterclockwise directions. Oscillatingmovement of the shaving tube 1270 helps to dislodge and release bonestock caught between the shaving rotor 1260 and shaving tube 1270.Constant or periodic oscillation of shaving tube 1270 about axis A10could be employed. Alternatively, constant or periodic rotation ofshaving tube 1270 in the same direction could be employed to dislodgetrapped bone stock. The gear train 1402 can be configured for any ofthese scenarios, or any combination thereof. Mechanisms by whichcontinuous rotating input motion in a single direction is converted toan oscillating angular output motion may be incorporated into the geartrain 1402. Such mechanisms include quick return or bell crankmechanisms, which are well known to those of ordinary skill in the art.

Shaving tube 1270 rotates, either in the same direction or oppositedirections at about 30 to 120 RPM. Owing to the helical geometry offlutes 1262, and the relatively slow rotation of shaving tube 1270compared to cutter 1048, as the cutter 1048 rotates cut soft tissue isaugered axially upwardly along cutter 1048 between the cutter 1048 andthe shaving tube 1270.

Two diametrically opposed debris windows 1290 are formed in shaving tube1270. Debris windows 1290 are located above and are axially spaced fromthe cutter windows 1272. Debris windows 1290 are also circumferentiallyarranged at a 90 degree offset about axis A10 from the cutter windows1272. Soft tissue that is cut from the bone stock during processing andaugered axially upwardly along shaving tube 1270 by shaving rotor 1260exits through the debris windows 1290.

A deflector ring 1292 is captured between bearing 1276 and shaving rotor1260 to deflect the cut and augered soft tissue out of the shaving tube1270 through the debris windows 1290. The deflector ring 1292 is coaxialwith cutter 1048 and has a frustoconical outer surface 1294 with itsdiameter increasing from bottom to top. The outer surface 1294 providesa deflection surface against which the soft tissue being augeredupwardly is urged radially outwardly and through the debris windows1290.

At the top of the deflector ring 1292 the diameter of the outer surface1294 is the same as or slightly smaller than the outer diameter ofbearing 1276. At the bottom of the deflector ring 1292 the diameter ofthe outer surface 1294 is smaller than the major diameter of the shavingrotor 1260 defined by the cutting edges 1264 at the radially outer edgesof the flutes 1262. This bottom diameter of deflector ring 1292 is thesame as the minor diameter of shaving rotor 1260 defined by the radiallyinnermost surfaces of cutter flutes 1262.

Debris catches 1296 receive from debris windows 1290 cut soft tissuethat has been augered upwardly along the shaving rotor 1260 between thecutter 1048 and the shaving tube 1270. The augered and deflected softtissue is collected on the debris catches 1296 for later use ordisposal.

A circular tumble plate 1298 is rotatably fixed to the coupler shaft1226. The bone stock sits on top of the tumble plate 1298 duringcleaning so that, when actuated, the tumble plate 1298 carries the bonestock to and from the cutter 1048. Referring to FIG. 31, tumble plate1298 has a central, D-shaped aperture 1300 that cooperates with D-shapedcross section of lower stub shaft 1254 that extends therethrough. Thecooperation between the D-shaped stub shaft 1254 and central tumbleplate aperture 1300 rotatably fixes the tumble plate 1298 to the cutter1048. During assembly, the D-shaped cross section passes through theD-shaped center aperture 1300 of tumble plate 1298 and into cooperatingD-shaped bore in coupler shaft 1226. Cutter 1048, tumble plate 1298, andcoupler shaft 1226 are thus rotatably fixed together for simultaneousrotation. During operation of system 1040, tumble plate 1298 is thusdriven about the central axis A10 by coupler shaft 1226.

The upper surface 1301 of the tumble plate 1298 carries the bone stock.In the embodiment shown, the upper surface 1301 is flat and smooth. Insome embodiments, the upper surface 1301 is textured or has grippingfeatures (not illustrated) to grip the bone stock and facilitate movingthe bone stock to the cutter 1048.

An arm 1302 extends over the planar upper surface of tumble plate 1298.When it is actuated, the arm 1302 moves across the tumble plate 1298between disengaged and engaged positions. In an extreme clockwiseposition, the arm 1302 is generally located along a periphery of thecircular tumble plate 1298.

FIG. 33 shows arm 1302 in a disengaged position. Arm front face 1304 isoriented so that, in a disengaged position, the front face 1304cooperates with the inwardly directed arcuate surface 1252 of thecontainment ring 1250 to further define the shell void space 1202. Thearm front face 1304 forms a nearly continuous surface with the inwardlydirected arcuate surface 1252 of containment ring 1250 when in thedisengaged position. When the arm 1302 is out of this disengagedposition and moving toward the cutter 1048 it diverts bone stock on therotating tumble plate 1298 toward the rotating cutter 1048.

FIGS. 34 and 35 show arm 1302 in an engaged position (bone stock notshown). When the arm 1302 is in an engaged position, the front face 1304guides bone stock toward the shaving rotor 1260 of cutter 1048 throughthe windows 1272 in shaving tube 1270. More particularly, bone stockcarried by the tumble plate 1298 is diverted by arm front face 1304toward the cutting edges 1264 of cutter 1048. Arm front face 1304 actsas a bearing surface that presses bone stock into windows 1272 andagainst the cutting edges 1264.

Referring specifically to FIG. 35, the front face 1304 abuts cylindricalouter surface 1377 of the shaving tube 1270 when the arm 1302 is in thisengaged position. In versions where the shaving tube 1270 rotates, thecylindrical outer surface 1377 of the shaving tube 1270 is in constantabutting contact with the front face 1304 to prevent the arm 1302 fromintruding on the cutter 1048 and to maintain a gap or spacing betweenthe front face 1304 and the cutter 1048.

When arm front face 1304 engages or is at least in close proximity toshaving tube 1270, but after some amount of bone cleaning takes place,shaving tube 1270 may be rotated about axis A10 to dislodge bone stocktrapped therein. The arm 1302 provides a bearing surface against whichtrapped bone stock can bear as it is loosened or dislodged from cutter1048 and/or shaving tube 1270 when the shaving tube 1270 rotates.

Referring to FIG. 36, arm 1302 includes a hub 1305 pivotally mounted tobase plate 1216. Hub 1305 is supported on pivot shaft 1306 for pivotalmovement between disengaged and engaged positions. The hub 1305 fitsover pivot shaft 1306. Pivot shaft 1306 has a radially extending annularflange 1308. Pivot shaft upper body 1310 extends upwardly from theflange 1308 into downwardly open bore 1312 in arm hub 1305. Fastener1314 locks the hub 1305 to the pivot shaft 1306. Fastener 1314 has ahead (not separately numbered) that sits in a counter bore 1316 in hub1305. Fastener 1314 further includes a threaded shaft (not separatelynumbered) depending downwardly from the fastener head. The threadedshaft extends into bore 1318 defined in hub 1305 below counter bore1316. Pivot shaft upper body 1310 has a threaded central bore (notseparately numbered) into which is received the threaded shaft offastener 1314 to fix arm 1302 to pivot shaft 1306.

Bearing 1320 is seated in a counter bore (not separately numbered) inthe base plate 1216. Downwardly-facing annular shoulder of pivot shaftflange 1308 axially abuts bearing 1320 in the base plate 1216. A spacer1322 surrounds pivot shaft upper body 1310 and is located between thearm 1302 and the upwardly-facing annular shoulder of the pivot shaftflange 1308. Spacer 1322 keeps arm 1302 spaced from the upper surface1301 of tumble plate 1298. Pivot shaft 1306 has a lower body 1324supported in bearing 1320 that extends through the counter bore in thebase plate 1216. Induced rotation of the pivot shaft lower body 1324imparts reversible pivoting motion of arm 1302 between its disengagedand engaged positions.

Pivot shaft upper body 1310 and bore 1312 of arm 1302 have complimentarynon-circular shapes that cooperate to rotatably fix pivot shaft 1306 andhub 1305. More particularly, they are each provided with diametricallyopposed flats, as shown in FIGS. 31 and 39. Pivot shaft 1306 and arm1302 are thus angularly fixed for rotating in unison.

Pivot shaft 1306 is operatively connected to the gear train 1402. Geartrain 1402 transfers torque received from base unit motor 44 throughreceiver head 1244 to pivot shaft 1306. Arm 1302 pivots upon actuationof pivot shaft 1306 by gear train 1402. The gear train 1402 can includemechanisms for transferring torque from the receiver head 1244 to thearm 1302 to reciprocate the arm between engaged and disengaged positionssuch as a quick-return mechanism or sliding crank mechanism.

The gear train 1402 is configured to limit the force provided by thefront face 1304 of arm 1302 against the bone stock such that only softtissue is cut from the bone stock without damaging the periosteum layer.The force can be limited by a force limiting clutch or otherfeature/mechanism in the gear train 1402. The force limiting feature isassociated with the arm 1302 so that the force with which the arm 1302presses bone stock into the cutter 1048 can be limited.

Arm 1302 is periodically reciprocated by the gear train 1402 betweenengaged and disengaged positions to reorient the bone stock trappedbetween the arm 1302 and the shaving tube 1270. The arm 1302 pivotsbetween the engaged and disengaged positions about 5 to 20 times perminute. The speed at which the arm 1302 pivots between the engaged anddisengaged positions is from 5 to 20 RPM. Movement of the arm 1302 maybe timed to the speed/motion of the shaving tube 1270 so that the arm1302 is in the engaged position when the shaving tube 1270 is actuated.

Referring to FIGS. 37-39, the arm 1302 has generally planar top 1326 andbottom 1328 surfaces. The arm hub 1305 has a semi-cylindrical or arcuateouter surface 1330 defined between the top 1326 and bottom 1328surfaces. The arm 1302 further includes planar rear 1332 and side 1334faces defined between the top 1326 and bottom 1328 surfaces. The rear1332 and side 1334 faces intersect the arcuate outer surface 1330. Therear face 1332 and side face 1334 are spaced from one another.

Rear face 1332 and side face 1334 lie in planes P1, P2, respectively,that are substantially transverse to one another. The planes P1, P2 lieat an acute angle α to one another. Spacing between the rear face 1332and side face 1334 increases as the faces 1332, 1334 extend further awayfrom the hub 1305.

Arm front face 1304 is arcuate in shape and is defined between the top1326 and bottom 1328 surfaces. The front face 1304 faces the cutter1048. A first edge 1336 of arm 1302 is formed at an intersection of thefront face 1304 and the side face 1334. The front face 1304 extends fromthe first edge 1336 to a terminus edge 1338. The terminus edge 1338 isformed at an intersection of end surface 1339 and front face 1304. Thearm 1302 in its engaged position adjacent the shaving tube 1270 definesan inwardly directed path along which the bone stock on the rotatingtumble plate 1298 is guided towards the center of shell void space 1202and the cutter 1048.

Referring to FIGS. 40-41, containment ring 1250 has a semi-cylindricalor arcuate wall 1340 that extends more than 180 degrees concentricallyabout axis A10. First 1342 and second 1344 wings are integrally formedat each end of the wall 1340. First wing 1342 is shaped to define arecess 1346 that receives a distal end of arm 1302 in a disengagedposition. Second wing 1344 is shaped to define a recess 1348 thatreceives a proximal end of arm 1302 in an engaged position.

Each wing 1342, 1344 has a threaded through bore 1350, 1352 forthreadedly receiving a set screw 1354, 1356. Set screws 1354, 1356extend through its threaded bore 1350, 1352 in containment ring 1250 andinto its recess 1346, 1348, respectively. The set screws 1354, 1356 areadjustable in bores 1350, 1352 to adjust a gap between the arm 1302 andthe wings 1342, 1344, and tune the extreme positions of the arm 1302 byadjusting the stop position of the arm 1302 in extreme clockwise andcounterclockwise positions. Set screws 1354 and 1356 abut arm rear face1332 and side faces 1334 to adjust and tune the extreme arm clockwiseand counterclockwise positions, respectively, of the arm 1302. Theterminal ends of the set screws 1354, 1356 act as stops for the arm 1302to prevent its over rotation into recesses 1346, 1348 as it moves intoits disengaged and engaged positions, respectively. In the extremecounterclockwise position arm 1302 is tuned so that front face 1304 isin contact with or nearly in contact with shaving tube 1270. In theextreme clockwise position arm 1302 is tuned so that front face 1304 isflush with or nearly flush with inner cylindrical surface 1252 ofcontainment ring 1250.

Threaded bores 1360 are formed axially through the arcuate wall 1340 andwings 1342, 1344 and mate with clearance bores (not illustrated) in baseplate 1216 and lower wall 1210. Threaded fasteners (not illustrated) arereceived from beneath into the clearance bores and the threaded bores1360 to attach the shell base lower wall 1210 and containment ring 1250to the base plate 1216.

As shown in FIGS. 42-44, fourteen flutes 1262 and corresponding cuttingedges 1264 are defined on shaving rotor 1260. Upper 1362 and lower 1364axial ends of shaving rotor 1260 are flat and lie in planesperpendicular to axis A10. Flutes 1262 and cutting edges 1264 extendbetween the ends 1362, 1364. The flutes 1262 and cutting edges 1264 arearranged such that they helically wrap less than 180 degrees aboutshaving rotor 1260 between ends 1362, 1364. The cutting edges each havea rake angle of between 0 and 10 degrees and more preferably have a rakeangle of 7 degrees.

Cutter upper stub shaft 1258 extends upwardly from shaving rotor 1260 toa chamfer 1366. Diametrically opposed flats 1368 are defined at an upperend of upper stub shaft 1258 through chamfer 1366. Upper stub shaft 1258is smooth and generally cylindrical between flats 1368 and shaving rotor1260. Cutter lower stub shaft 1254 extends downwardly from shaving rotor1260 to a chamfer 1370. Lower stub shaft 1254 is smooth and generallycylindrical between flat 1256 and shaving rotor 1260.

Referring to FIGS. 45-47, shaving tube 1270 is generally cylindrical forfitting over cutter 1048. As shown in FIG. 45, the shaving tube 1270 hasdiametrically opposed cut-outs 1372 formed in its cylindrical wall (notseparately numbered) that define the cutter windows 1272. Cut-outs 1373are also formed in the shaving tube wall to define the debris windows1290.

Cut-outs 1372 create the sharp shaver edges 1274 that cut soft tissueentering cutter windows 1272. A shaver edge 1274 is located on bothsides and the top of each cutter window 1272. Thus, the shaver edges1274 further define the top and sides of the cutter windows 1272. Sills1374 at the bottoms of the shaving tube windows 1272 formed by thecut-outs 1372 are generally flat and parallel with the upper surface1301 of the tumble plate 1298.

In the shown embodiment, the cut-out edges of each cutter window 1272form a continuous shaver edge 1274. However, in alternative embodiments,separate and distinct shaver edges may be provided along the sides andtop of each window 1272. The shaver edges 1274 are located so that softtissue trapped between shaving rotor 1260 and the inner cylindrical wallof shaving tube 1270 is cut by the shaver edges 1274 either at the sidesor at the top of the cutting windows 1272.

A base 1376 of the shaving tube 1270 is located below the cutter windows1272. In versions where the shaving tube 1270 rotates, the cylindricalouter surface 1377 of the shaving tube 1270 is in constant abuttingcontact with the front face 1304 of arm 1302 via the base 1376 tomaintain a gap or spacing between the front face 1304 and the cutter1048.

Referring to FIGS. 48-50, the debris catches 1296 include arcuate mounts1378 by which the debris catches 1296 are attached to the shaving tube1270. As best shown in FIG. 48, the arcuate mounts 1378 include tubehalves 1380. Tube halves 1380 mate with one another to form an outertube structure (not separately numbered) located coaxially about shavingtube 1270. Mounts 1378 have male projections 1382, 1383 that extend fromthe tube halves 1380 and mating female notches 1384, 1385 recessed inthe tube halves 1380. The male and female mating projections 1382, 1383and notches 1384, 1385 engage one another to align the tube halves 1380and form the outer tube structure. The mating features 1382, 1383, 1384,1385 and tube halves 1380 are secured to one another by adhesive,fasteners, or the like.

Referring to FIG. 49, debris windows 1392 are formed in each tube half1380. The debris windows 1392 are aligned with the shaving tube debriswindows 1290. More particularly, alignment protrusions 1387 act to alignthe windows 1290, 1392. Alignment protrusions 1387 extend inwardly froma semi-cylindrical inner surface of tube halves 1380 on each side of thedebris windows 1392. Alignment protrusions 1387 are dimensioned andshaped for receipt into the shaving tube debris windows 1290 adjacentthe opposite side edges of the cutouts 1373. The protrusions 1387provide axial alignment of the windows 1290, 1392 their opposite endsabutting the opposite top and bottom edges of cutouts 1373. Protrusions1387 provide radial alignment of the windows 1290, 1392 by theirabutting contact with the respective side edges of cutouts 1373.

Catch trays 1386 are attached to each arcuate mount 1378 below debriswindows 1392. Cut soft tissue that has been augered along the interiorof the shaving tube 1270, and deflected by deflector ring 1292 radiallyoutwardly through debris windows 1290 passes through aligned debriswindows 1392 and is deposited onto the catch trays 1386 where the softtissue and other debris is ultimately collected. Each catch tray 1386includes a bottom 1388 and a peripheral wall 1390 extending upwardlyfrom the bottom 1388. Peripheral wall 1390 holds and contains the softtissue and other debris deposited on the bottom 1388.

A lid 1500 is removably positionable on top of the containment ring 1250of shell 1200 (see FIG. 30). The lid 1500 covers the shell void space1202 and the bone stock being cleaned. The lid 1500 has a slot 1502 foraccepting the shaving tube 1270 when sliding the lid 1500 in place overthe shell void space 1202. A handle 1504 is fixed to the lid 1500.Handle 1504 extends upwardly from the lid 1500 to be grasped by theuser. The user can slide the lid in place over the containment ring 1250and beneath the debris catches 1296 or remove the lid 1500 using thehandle 1504.

During operation, uncleaned bone is first placed in the shell void space1202 for cleaning and the lid 1500 is then slid into place atopcontainment ring 1250 to cover the void space 1202. Fasteners (notillustrated) may be used to fasten the lid 1500 to the containment ring1250 via threaded bores 1360. The uncleaned bone includes soft tissueattached thereto that requires removal without damaging the periosteumlayer.

The alternative cleaning module 1046 is then fitted to the base unit 42.The surgical personnel actuate the alternative cleaning module 1046 bydepressing the push button of base unit switch 98. In response to thedepression of switch 98 the motor controller (not illustrated) causespower to be applied to the motor 44, which energizes the motor 44 andcauses its output shaft 78 to turn in a direction that drives rotationof cutter 1048 counterclockwise as viewed from above.

The tumble plate 1298 rotates in unison with the cutter 1048 in thecounterclockwise direction. Tumble plate 1298 operates to carry the bonestock toward the front face 1304 of arm 1302 when the arm is out of itsdisengaged position. In the engaged position, arm front face 1304 guidesthe bone stock toward shaving tube 1270 and the cutter shaving rotor1260 to cut soft tissue from the bone stock.

Cutting edges 1264 of shaving rotor 1260 and/or shaver edges 1274 ofshaving tube 1270 cut away soft tissue from bone. The cut soft tissueand other debris is then augered upwardly between the shaving rotor 1260and shaving tube 1270. The augered tissue is deflected radiallyoutwardly by deflector ring 1292 into and through the debris windows1290 in shaving tube 1270 and windows 1392 in each tube half 1380. Thetissue is then collected onto catch trays 1386 for disposal. Thisprovides a separation of soft tissue and other debris from the remainingbone of the bone stock.

After some amount of bone cleaning takes place, drive assembly 1400rotates shaving tube 1270 about axis A10 to dislodge bone stock trappedtherein. The arm 1302 provides a bearing surface against which trappedbone stock can bear as it is loosened or dislodged from cutter 1048and/or shaving tube 1270 when the shaving tube 1270 rotates. The geartrain 1402 is configured so that the shaving tube 1270 rotates aboutaxis A10 between 0 and 360 degrees once every 1 to 5 seconds and inalternating clockwise and counterclockwise directions.

During cleaning, drive assembly 1400 periodically pivots arm 1302between engaged and disengaged positions to reorient the bone stocktrapped between the arm 1302 and the shaving tube 1270. The arm 1302pivots between the engaged and disengaged positions about 5 to 20 timesper minute. This further facilitates removal of soft tissue and debrisfrom all surfaces of the bone stock.

Once the alternative cleaning module 1046 has sufficiently removed softtissue from the bone, the lid 1500 is removed. The catch trays 1386, andsoft tissue/debris collected in the catch trays 1386 are removed anddiscarded. Next, the cleaned bone is grabbed by forceps or other device(not illustrated) for further processing. At the conclusion of thecleaning process, the alternative cleaning module 1046 is removed fromthe base unit 42. The alternative cleaning module 1046 may then becleaned or discarded.

Obviously many modifications and variations of the present invention arepossible in light of the above description. While this description isdirected to particular embodiments, it is understood that those skilledin the art may conceive of modifications and/or variations to thespecific embodiments shown and described herein. Any such modificationsor variations, which fall within the purview of this description, areintended to be included herein as well. It is understood that thedescription herein is intended to be illustrative only and is notintended to be limited.

What is claimed is:
 1. An assembly for cleaning bone stock, saidassembly comprising: a shell having a base and a top located above thebase, the shell defining a void space for receiving bone stock; a tumbleplate having an upper surface; a cutter disposed in the void space andconfigured to remove soft tissue from bone stock; and a guide movableacross the upper surface of the tumble plate between a disengagedposition and an engaged position, wherein the guide is configured tomove bone stock received in the void space toward the cutter when out ofthe disengaged position.
 2. The assembly of claim 1, wherein the guideis an arm formed to have a containment wall that defines a bone stockspace in which bone stock is placed.
 3. The assembly of claim 1, furtherincluding a biasing device that biases the guide towards the engagedposition.
 4. The assembly of claim 1, wherein the cutter includes atleast one cutting edge and is rotatably mounted to the base so as to bedisposed in the void space.
 5. The assembly of claim 4, furthercomprising a shaving tube disposed around the cutter, the shaving tubehaving at least one shaving edge that is located adjacent the at leastone cutting edge of the cutter.
 6. The assembly of claim 5, wherein theshaving tube is formed to define a window and the at least one shavingedge at least partially defines the window.
 7. The assembly of claim 6,wherein: the shaving tube is further formed to have at least one debriswindow through which cut tissue passes that is separate from the windowdefined by the at least one shaving edge; and a debris catch is mountedto the shaving tube to receive the tissue that passes through the atleast one shaving tube debris window.
 8. The assembly of claim 7,wherein the cutter includes a plurality of cutting edges that arepositioned to rotate adjacent the at least one shaving edge of theshaving tube so that the at least one shaving edge and the plurality ofcutting edges cooperate to cut soft tissue from bone stock.
 9. Theassembly of claim 8, wherein the cutter is formed to have plural flutesthat define the plurality of cutting edges of the cutter that arepositioned to rotate adjacent the shaving edge of the shaving tube sothat the at least one shaving edge and the plurality of cutting edgescooperate to cut the soft tissue from bone stock and the flutes areshaped and the cutter rotates relative to the shaving tube so that, asthe cutter rotates, cut tissue is augured upwardly between the shavingtube and the cutter.
 10. The assembly of claim 8, wherein the shavingtube has a top end, and wherein a structural member defining acollecting surface is located adjacent the top end of the shaving tubefor receiving cut tissue augered between the shaving tube and thecutter.
 11. The assembly of claim 1, wherein the tumble plate extendsaround the cutter.
 12. The assembly of claim 1, wherein the tumble plateis seated in the void space of the shell such that bone stock sits ontop of the tumble plate and the tumble plate is able to rotate so as toreorient bone stock.
 13. The assembly of claim 5, wherein a driveassembly is at least partially attached to the shell, and the driveassembly is adapted to be transfer torque from a motor to the cutter andthe shaving tube.
 14. The assembly of claim 13, wherein the shell isformed with at least one lock feature configured to cooperate with acomplementary lock feature attached to a base unit that includes a motorable to actuate the drive assembly so that the lock feature attached tothe shell and the base unit releasably locks the shell to the base unit.15. The assembly of claim 13, wherein the drive assembly is configuredto continually rotate the cutter while periodically rotating the shavingtube.
 16. The assembly of claim 13, wherein the drive assembly isconfigured to rotate the shaving tube in one of the following motionsrelative to the rotation of the cutter: a same direction; a reversedirection; or an oscillatory motion.
 17. A bone stock cleaning assembly,said assembly including: a shell having a base and a top located abovethe base, the shell defining a void space for receiving bone stock; acutter formed with at least one cutting edge that is rotatably mountedto the base so as to be disposed in the void space; a tumble platedefined by the base and having an upper surface; and a containment wallwithin the void space, the containment wall defining a bone stock spacedisposed on the upper surface of the tumble plate wherein thecontainment wall is moveably mounted to the base so that the containmentwall is able to move transverse to the upper surface between adisengaged and an engaged position to corral bone stock so that bonestock is trapped and pressed into the cutter.
 18. The assembly of claim17, further comprising a shaving tube disposed around the cutter, theshaving tube being formed to have at least one shaving edge that islocated adjacent the cutting edge of the cutter.
 19. The assembly ofclaim 18, wherein the shaving tube is formed to define a window and theat least one shaving edge at least partially defines the window.
 20. Theassembly of claim 19, wherein the cutter is formed to have a pluralityof flutes that define a plurality of cutting edges of the cutter thatare positioned to rotate adjacent the shaving edge of the shaving tubeso that the at least one shaving edge and the plurality of cutting edgescooperate to cut soft tissue from bone stock and the flutes are shapedand the cutter rotates relative to the shaving tube so that, as thecutter rotates, cut tissue is augured upwardly between the shaving tubeand the cutter.
 21. The assembly of claim 20, wherein the shaving tubehas a top end, and wherein a structural member defining a collectingsurface is located adjacent the top end of the shaving tube forreceiving cut tissue augered between the shaving tube and the cutter.22. The assembly of claim 17, wherein the tumble plate extends aroundthe cutter.
 23. The assembly of claim 17, wherein the tumble plate isseated in the void space of the shell such that bone stock sits on topof the tumble plate and the tumble plate is able to rotate so as toreorient bone stock.
 24. A method of cleaning bone stock with a cleaningmodule comprising a shell defining a void space for receiving bone stockto be prepared, a cutter disposed in the void space, a tumble platehaving an upper surface, and a guide movable across the upper surface ofthe tumble plate, the method comprising the steps of: placing bone stockinto the void space; actuating the cutter; and moving the guide acrossthe upper surface of the tumble plate between a disengaged position toan engaged position to move bone stock received in the void space towardthe cutter to cut soft tissue and other debris from bone stock.
 25. Themethod of claim 24, further comprising a shaving tube disposed aroundthe cutter, the shaving tube being formed to have at least one shavingedge that is located adjacent a cutting edge of the cutter, wherein theshaving tube is formed to define a window and the at least one shavingedge at least partially defines the window.
 26. The method of claim 25,wherein the tumble plate extends around the shaving tube.
 27. The methodof claim 25, wherein the cutter is formed to have plural flutes thatdefine plural cutting edges of the cutter that are positioned to rotateadjacent the shaving edge of the shaving tube so that the at least oneshaving edge and the plurality of cutting edges cooperate to cut softtissue from bone stock and the flutes are shaped and the cutter rotatesrelative to the shaving tube so that, as the cutter rotates, cut tissueis augured upwardly between the shaving tube and the cutter.
 28. Themethod of claim 25, wherein the shaving tube has a top end, and whereina structural member defining a collecting surface is located adjacentthe top end of the shaving tube for receiving cut tissue augered betweenthe shaving tube and the cutter.
 29. The method of claim 25, wherein theshaving tube rotates at about 30 to 120 RPM when the cutter is actuated.30. The method of claim 24, further comprising the step of mounting theshell in a pedestal mounting space of a base module.
 31. The method ofclaim 24, further comprising the step of removing the cleaning modulefrom a base module.
 32. The method of claim 31, further comprising thestep of discarding the cleaning module.
 33. The method of claim 31,further comprising the step of cleaning the cleaning module for reuse.